1. mare has higher risk of contracting an STD from a stallion than vice versa2. stallion is usually only a carrier & exhibits no clinical signs of disease3. STD's transmitted through cooled fresh or frozen semen

problems associated with STDs in mares (4)

1. lost breeding season for the mare2. lost pregnancy3. sick or dead neonate4. worst case: STD spreads to all the mares on the farm → farm is shut down for the breeding season